The present invention relates to a predictive display and, in particular, it concerns a predictive display for a system having delayed feedback of a command issued.
By way of introduction, remotely operated devices generally require feedback from the device to the operator, so that the operator can decide on what action to take next. This is generally achieved by having a video camera or other similar apparatus disposed on the device. The video camera then relays feedback of the position of the device with respect to its surroundings. However, there is a time delay, typically of up to several seconds, between the time when the operator gives a movement command to the device and when the operator receives feedback with respect to the completion of the movement command. The delay is typically due to several factors. First, there may be a transmission time delay due to communication from the operator to the device and from the device to the operator. Second, there is a time delay due to the time taken by the device to carry out the movement command. Therefore, the operator needs a prediction of the final position of the device at the time the movement command is being created to be able to decide whether the movement command is appropriate. A solution taught by the prior art is to superimpose an icon such as a motion vector or arrow to represent the movement command. The beginning of the vector or arrow denotes the current position and the end of the vector or the arrowhead denotes the predicted position after the movement command has been carried out or the predicted position after a predetermined time interval. A shortcoming of the aforementioned system is due to the system not being intuitive to the operator. An operator needs to pay close attention to the arrow or vector. A further shortcoming of the aforementioned system is that the image of the view from the device as well as the superimposed vector are updated as the device moves, causing further confusion to the operator as well reduced operator performance.
There is therefore a need for an intuitive predictive display for a system having delayed feedback of a command issued.